php-fpm custom settings saved but not loaded

Hi,
I installed ISpconfig 3.0.5 on a Ubuntu 14.04 "Trusty Tahr" LTS in october and I'm really fine with it.
Using fast-cgi with old php 5.2 on some websites, and php-fpm with php 5.5.9 for others...
Anyway I've got 2 pbs related to php-fpm, I'll make a post for each, for the sake of clarity...

It appears that I can't change anymore the php settings values for any of my php-fpm sites, despite repeating all steps several times
As per the manual, I wrote some settings in the custom settings form in the options tab of Ispconfig UI.